<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="vue.js"></script>
    <style>

    </style>
</head>
<body>
<!--<div id="app" @click="handleClick" :class="{activated: isActivated}">-->
<!--
    <div id="app" @click="handleClick" :class="[activated,activatedOne]">
-->
<div id="app">
    <!--<div   v-if="show==='user'">this is A</div>-->
    <!--<div   v-else-if="show==='b'">this is B</div>-->
    <!--<div   v-else>this is {{show}}</div>-->
    <!--<div   v-show="show">{{message}}</div>-->
    <div v-if="show">
        username:<input key="username"/>
    </div>
    <div v-else>
        email:<input key="email"/>
    </div>
</div>
<script>
    var vm = new Vue({
        el:'#app',
        data:{
            show:false,
            message:'hello world'
        },

    methods:{

    }

    })














</script>
</body>
</html>